Sound-generating (sonic) motor system in a teleost fish (Porichthys notatus): sexual polymorphisms and general synaptology of sonic motor nucleus

The sonic motor nucleus of the plainfin midshipman, Porichthys notatus, is a midline nucleus located at the junction of the caudal medulla and rostral spinal cord. Its motoneurons innervate sonic "drumming" muscles that are attached to the lateral walls of the swimbladder. There are two classes of sexually mature males referred to as Type I and Type II. The Type I males are larger and generate sounds during the breeding season. The Type II males are smaller and, like adult females, have not yet been shown to generate sounds. This study examined possible sex differences in the size of sonic motoneurons, and the type and distribution of their afferent terminal boutons. The average soma diameter of motoneurons of Type I males is about 50% larger than that of Type II males and females. There is also a small but significant difference in soma diameter between Type II males and females; they are smaller in the former class. There were no sex differences in the presence or distribution of different classes of axosomatic and axodendritic terminal boutons, which included: (1) active zones with either clear, round, or pleomorphic vesicles, (2) active zones with both clear, round vesicles, and larger dense core vesicles, (3) "mixed synapses" with gap junctions and active zones usually associated with pleomorphic vesicles. The results are discussed within the context of sexual differentiation of vertebrate motor systems and the functional organization of the sonic motor system in fishes. Sex differences in soma diameter correlate with a number of sex differences in the gross and ultrastructural features that distinguish the sonic muscles of Type I males from those of Type II males and females, which are similar to each other. The absence of qualitative sex differences in synaptic morphology suggest that the central neuronal circuitry of the sonic motor system is similar among all three adult morphs.     

Development of vasoactive-intestinal-polypeptide-immunoreactive neurons in the rat occipital cortex: a combined immunohistochemical-autoradiographic study

The postnatal development of vasoactive intestinal polypeptide (VIP)-immunoreactive neurons, previously labeled with [3H]thymidine on embryonic days E14-E22, has been studied in the rat occipital cortex. Immuno-histochemistry combined with autoradiography showed very little evidence of an "inside-out" pattern of maturation. Most VIP neurons are generated between E17 and E21 and are found in layers II-IV of the cortex, but their position within these layers is not dictated by their date of birth. There is evidence of a temporal maturation since E17 VIP neurons were seen first (at day 7) and E21 last. Peak numbers of VIP neurons were generated on E19. The numbers of VIP-immunoreactive neuronal somata detected in the cortex increased from the first week after birth to the third week and declined thereafter. However VIP-immunoreactive dendrites were still visible, suggesting that VIP levels in the cell bodies were very low, and not that there was a loss of neurons.     

Stromal cells in hemangioblastoma: neuroectodermal differentiation and morphological similarities to ependymoma

The histogenesis of stromal cells in hemangioblastoma is inconclusive despite a long-term controversy. An immunohistochemical and ultrastructural study was conducted for 17 cases of cerebellar hemangioblastoma. A wide range of immunohistological markers, targeting epithelial, mesenchymal, endothelial and neuroectodermal tissues, was used. In all cases, the microscopic hallmark characterizing hemangioblastomas, that is, lipid-containing stromal cells and a fine capillary network, known as a reticular variant, was noted. Stromal cells showed a variable immunoreactivity for neuroectodermal markers, such as S-100 protein, CD56, CD57, CD99, and neuron-specific enolase. This result, in conjunction with the absence of immunoreactivity for epithelial, mesenchymal, and endothelial markers, likely suggests neuroectodermal differentiation of stromal cells. In three cases, another component, known as a cellular variant, where epithelioid tumor cells were arranged in nests encircled by capillaries and/or in pseudorosette-like structures, was noted. Glial fibrillary acidic protein-immunoreactivity, which was totally absent in cases only showing the reticular pattern, was noted in two of them, suggesting a distinctive sign of glial differentiation in a proportion of hemangioblastomas. Ultrastructurally, microvilli-like projections in intracytoplasmic vacuoles were demonstrated in stromal cells. This result, taken together with the neuroectodermal hypothesis of stromal cells, suggests that hemangioblastomas may occasionally exhibit morphological similarities to ependymomas.     

Synergistic action of immunostimulatory DNA and fcgamma receptor IIB-crosslinking on B-cell phenotype and function

CpG DNA functions via the toll-like receptor-9 (TLR-9) receptor, inducing B cell proliferation and promoting immunoglobulin production. B cell responses to CpG DNA-containing immune complexes could be important in chronic autoimmunity and immune responses to bacterial components. Therefore, we investigated the potential synergy of CpG DNA-stimulation with FcgammaR clustering (CFR) on splenic B cell activity. CFR-induced splenocyte proliferation was significantly increased compared to treatment with CpG DNA alone. While the levels of interleukin-10 (IL-10) were increased in CpG DNA-treated splenocyte cultures, particularly following FcgammaRII/III-clustering, CFR treatment reduced IL-6 levels. B-cell maturation in culture was enhanced by CFR. Indeed, the frequency of IgG expressing cells after stimulation with CpG DNA was increased and was even higher after CFR stimulation. Furthermore, the frequency of plasma cell precursors was markedly increased by stimulation with CFR. Late splenic B cell subsets, transitional type 2 (T2) and mature (M) B cells, responded strongly to CpG DNA with proliferation and the response was enhanced by FcgammaR-clustering. Immature transitional type 1 (T1) B cells showed distinctly lower proliferative response to CpG DNA and very small effects of FcgammaR-clustering, despite similar expression of Fcgamma-receptors by all B cell subsets. In conclusion, these data show synergistic impact of CpG DNA and simultaneous FcgammaR-clustering on B cell proliferation and differentiation.     

Altered splenic B cell subset development in mice lacking phosphoinositide 3-kinase p85alpha

The signaling enzyme phosphoinositide 3-kinase (PI3K) is activated following B cell receptor (BCR) engagement and by many other receptors on B lymphocytes. Mice lacking p85alpha, the predominant PI3K regulatory isoform, exhibit defects in B cell development and activation that are grossly similar to those found in mice lacking Bruton's tyrosine kinase (Btk) and other critical signaling molecules. However, a detailed analysis of splenic B cell subsets in p85alpha-deficient mice has not been reported. Here we show that these mice are deficient in four major B cell subsets: transitional-1, transitional-2, follicular and marginal zone. These defects are distinct from those observed in Xid mice that express a mutant Btk unable to interact with PI3K lipid products. Moreover, mice with both genetic lesions exhibit even greater impairment in B cell development. Finally, we show that transgenic expression of the anti-apoptotic protein Bcl-2 in p85alpha-deficient mice restores the transitional B cell subsets but not the marginal zone subset, and produces a follicular population with an aberrant phenotype. These findings establish a role for PI3K-p85alpha in differentiation of both follicular and marginal zone B cells, and suggest that these functions are required not solely for the propagation of anti-apoptotic signals.     

川芎嗪诱导大鼠骨髓间质干细胞分化为神经元样细胞的研究

目的用川芎嗪(ligustrazin hydrochloride)在体外定向诱导SD青年鼠骨髓间质干细胞(mesenchymal stem cells，rMSCs)分化为神经元样细胞。方法用低糖DMEM冲洗骨髓腔，收集骨髓细胞悬液，接种在塑料培养瓶中。经体外扩增、纯化，选用第5代后的骨髓间质干细胞进行诱导分化。用10μg／LbFcF预诱导24h，更换成含川芎嗪的无血清培养基DMEM诱导间质干细胞分化为神经元样细胞。用免疫组织化学SABC法鉴定神经丝蛋白(NF—M)、神经元特异性烯醇化酶(NSE)、巢蛋白(nestin)、微管联合蛋白-2(MAP-2)、生长相关蛋白-43(GAP-43)、胶质纤维酸性蛋白(GFAP)的表达。结果第5代间质干细胞形态达到均一，呈梭形。用川芎嗪诱导15min到3h，间质干细胞胞体逐渐增大，并伸出细长突起形似神经元样细胞。免疫组织化学显示NF-M、NSE、nestin、MAP-2和GAP-43表达阳性，而GFAP阴性。对照组上述染色均为阴性。结论川芎嗪可诱导骨髓间质干细胞分化为神经元样细胞。     

GM and KM allotypes in eight tribal populations of madyha Pradesh and Orissa, India

Summary Serum samples from eight endogamous Indian tribal populations of Madhya Pradesh (Dhurwa, Halba, Bhatra, Muria, Maria) and Orissa (Deshia Khond, Binjhal, Kisan) with a total of n=731 unrelated individuals were typed for G1M (1,2,3,17), G3M (5,10,11,13,14,15,16,21,26), and KM (1). In seven of these populations five different GM haplotypes were found:GM*1,17;21,26; GM*1,17;10,11,13,15,16; GM*1,2,17;21,26; GM*1,3;5,10,11,13,14,26; andGM*3;5,10,11,13,14,26. In the Kisan sample the haplotypeGM*1,2,17; 21,26 is absent. The intergroup variability in the distribution of these haplotypes is considerable and statistically highly significant. The reasons for that can be attributed to the ethnohistory and to the genetic isolation of these eight endogamous tribal populations. The GM haplotype distribution pattern of all these groups is quite different from that of the non-tribal populations of India, whereas it is in good agreement with that of the so far tested other tribal populations from India. This can be explained by different origin and history of the Indian tribal and non-tribal populations. In the KM system, too, remarkable variability is seen in the distribution of phenotype and allele frequencies among the eight tribal populations under study.     

脐血CD34+细胞体外定向诱导分化为T淋巴细胞的实验研究

目的：建立利用人造血干／祖细胞体外定向诱导分化为T淋巴细胞的方法，为研究T细胞生物学特性及细胞免疫提供技术平台。方法：MACS方法分离人脐带CD34^ 细胞接种到人胎儿胸腺基质单层细胞上，IMDM液体培养基含20％人AB血清并加入FL、IL-12、IL-7和IL-2细胞因子组合，于培养7、14、21、28、35、42天取非贴壁细胞利用流式细胞仪对细胞表型进行检测，并进行细胞形态学分析。结果：2周后，CD4^ CD8^ 非成熟T淋巴细胞占细胞总数的0．3％-13．3％，4-5周CD4^ CD8^ T淋巴细胞达到高峰占16．6％-26．5％，且CD3^ CD4^ CD8^ 和CD3^ CD4^-CD8^ T淋巴细胞逐渐增多，6周后达26．5％～64．9％和11．6％-38．9％。培养成熟的T淋巴细胞经PHA IL-2刺激后瑞氏染色鉴定可见大原始淋巴细胞存在。结论：利用人脐血CD34^ 在体外人胎儿胸腺基质单层细胞上加FL、IL-12、IL-7和IL-2细胞因子组合条件下，可诱导分化出T淋巴细胞，并且培养的T细胞对有丝分裂素刺激有增殖反应。     

自体甲状腺组织与干细胞移植治疗甲状腺功能减退症的研究进展

不可逆性甲减患者需要终身服用甲状腺激素，对患者的日常工作和生活造成了很大的不便。随着近年来对自体甲状腺组织与干细胞移植研究的进展，有望解决甲减病人终身服药这一问题。自体甲状腺组织移植的动物实验以及人体试验均表明：甲状腺移植物不但能够存活，而且能够发挥作用。最新的胚胎干细胞（Embryonic stemcell，ESC）研究证明，ESC可以分化为甲状腺滤泡细胞。